Exhibit A JOINT FILING AGREEMENTJoint Filing Agreement • February 14th, 2013 • Blackstone Holdings II L.P. • Petroleum refining
Pursuant to and in accordance with the Securities Exchange Act of 1934, as amended, and the rules and regulations thereunder (the “Exchange Act”) the undersigned hereby agree to the joint filing of Blackstone PB Capital Partners V Subsidiary L.L.C., Blackstone PB Capital Partners V-AC L.P., Blackstone Family Investment Partnership V USS L.P., Blackstone Family Investment Partnership V-A USS SMD L.P., Blackstone Participation Partnership V USS L.P., Blackstone PB Capital Partners V L.P., Blackstone Management Associates V USS L.L.C., BMA V USS L.L.C., BCP V USS Side-by-Side GP L.L.C., Blackstone Family GP L.L.C., Blackstone Holdings II L.P., Blackstone Holdings I/II GP Inc., The Blackstone Group L.P., Blackstone Group Management L.L.C. and Stephen A. Schwarzman, on behalf of each of them of any filing required by such party under Section 13 or Section 16 of the Exchange Act or any rule or regulation thereunder (including any amendment, restatement, supplement, and/or exhibit thereto) wi
